Dense fog is more widespread this morning than any morning so far this winter. The fog extends from southwest of Bakersfield clear into the lower Sacramento Valley. Some of the foothill communities are still in the clear, but it is approaching Lindsay and Porterville. This is one of those classic winter mornings where a race between the frost and the fog was played out last night.
Upper level high pressure is now just off shore and will move overhead Monday. With a strong warm air inversion, some areas may not clear out at all this afternoon and again Monday and Tuesday afternoons. Temperatures over the next few days will range from the mid to upper 40s where the low clouds remain persistent to upper 50s and lower 60s where hazy sunshine prevails, primarily in Kern County.
Beginning late Tuesday, the pattern will become more complex. A weak upper low will approach the south central coast Wednesday and Christmas Eve. For now, the chance of rain appears very low. However, the counterclockwise flow around the system may rotate increasing amounts of mid and high level clouds. While that’s occurring, a strong low will be moving through the Pacific Northwest, diving into the Rocky Mountain and Midwest regions Wednesday and Thursday. A very strong surface high will build over the Great Basin behind this system which will generate a strong ofof shore flow.
In the meantime, at the upper levels of the atmosphere, a sharp ridge over the eastern Pacific will stretch all the way into Alaska and northwest Canada. This will allow an arctic air mass to barrel south into the Rockies and Midwest. Fortunately, it appears this air mass will remain far enough to the east to prevent much of an impact on our region.
Models still show a good trend this morning in the potential of a vigorous trough of low pressure moving into California Friday night and Saturday. This system will move eastward perpendicular to the Sierra Nevada which means lift could potentially wring out heavy amounts of rain and snow over the higher elevations. Models also show another potentially strong system moving through about a week from tomorrow.
Forecast: Widespread dense fog this morning, lifting into a low overcast. Clearing in some areas this afternoon, especially in Kern County and near the base of the foothills. Widespread night and morning fog and low overcast will continue through Tuesday with partial afternoon clearing. From Tuesday night through Christmas Eve, expect periods of night and morning fog and low clouds with variable cloudiness above the fog. Increasing cloudiness Christmas Day leading to a chance of rain late Friday night, rain becoming likely Saturday. a chance of showers Saturday night. mostly to partly cloudy Sunday.
Short Term:
Madera 51/30/50/32/51 | Reedley 52/29/51/32/51 | Dinuba 50/29/51/33/50 |
Porterville 56/29/53/30/52 | Lindsay 55/28/53/30/52 | Delano 53/30/52/32/52 |
Bakersfield 57/36/62/37/57 | Taft 57/45/62/46/57 | Arvin 58/33/63/34/57 |
Lamont 58/32/61/34/57 | Pixley 53/29/52/31/51 | Tulare 51/30/50/33/50 |
Woodlake 54/29/53/31/52 | Hanford 51/31/50/33/50 | Orosi 54/28/52/30/52 |
Seven Day Forecast:
Wednesday
AM fog/variable clouds 34/54 |
Christmas Eve
AM fog/variable clouds 35/55 |
Christmas Day
PM rain possible 37/62 |
Saturday
Rain likely 42/58 |
Sunday
AM showers possible 41/57 |
Two Week Outlook: December 27 through January 2: The chance of rain is certainly there early in the period. This model is also indicating near to marginally below average temperatures during this period.
January: This model doesn’t really show a trend for temperatures at all. We’ll call it near average this time around. Not surprisingly, it does indicate January will have below average precipitation, as has been the case this La Nina year.
January, February, March: This model does not really offer much hope for a decent rainy season as below average precipitation is indicated over the Golden State. Temperatures over this 90 day period will be generally above seasonal average.
Winds Discussion: Winds through Wednesday will be generally less than 10 MPH late mornings and afternoons and at or less than 5 MPH during the night and early morning hours with extended periods of near calm conditions.
Rain Discussion: Expect dry weather through Christmas Day. I hedge just a bit for Wednesday and Thursday as a weak upper low approaches the southern California coast. It’s possible a few sprinkles could occur, mainly in the south valley, but measurable rain is unlikely.
That will begin to change Friday night as a rather vigorous trough of low pressure will potentially move through Saturday. models the past few days have been consistent in showing precipitation over the entire region, especially on Saturday. This storm will be running west to east, perpendicular to the Sierra Nevada, which means there will be good lift along the Sierra Nevada for the possibility of a strong precipitation event.
About a week from tomorrow, another low shows up on models moving this time through central and southern California. We’ll study this potential in the coming days.
Frost Discussion: Last night was a classic race between the fog and the frost. Widespread upper 20s and lowe r30s occurred before the fog took over. As of 6:30, the coldest I could find was 27 in Lindsay and 28 at Porterville and McFarland.
The fog is more widespread this morning than any morning so far. When the sun comes up and daytime heating occurs, weak as it may be, the fog will begin to lift and move into the lower foothills. It’s possible some areas may not see the sun this afternoon, especially towards the center of the valley.
Tonight through at least Tuesday morning, there will continue to be at least two possible outcomes each night. areas under a low cloud deck will remain above freezing while areas that clear out this afternoon will again drop into the upper 20s and lower 30s unless fog develops early enough to halt the radiational cooling process.
The numbers below are calculated under the assumption that the various locations will be relatively clear for much of the night. if fog and low clouds bless your location, so much the better.
By Tuesday night, a weak upper low will be approaching the southern California coast. Theoretically, this would throw some cloud cover overhead, but this remains to be seen. Later in the week, there will be a greater chance of cloud cover keeping temperatures above freezing. There is one wild card, however. As a strong arctic air mass engulfs the interior west, a strong off shore flow will develop over California. Hopefully it will not mix down to the valley floor, mixing out fog and lower dew points as it does. This is something we’ll just have to watch the next couple of days.
Lows Tonight:
Terra Bella
29 |
Porterville
29 |
Ivanhoe
28 |
Woodlake
29 |
Strathmore
29 |
Mcfarland
28 |
Ducor
30 |
Tea Pot Dome
29 |
Lindsay
28 |
Exeter
29 |
Famoso
29 |
Madera
30 |
Belridge
28 |
Delano
29 |
North Bakersfield
29 |
Orosi
28 |
Orange Cove
29 |
Lindcove
29 |
Lindcove Hillside
Af |
Sanger River Bottom
27 |
Root Creek
28 |
Venice Hill
29 |
Rosedale
30 |
Jasmine
30 |
Arvin
32 |
Lamont
32 |
Plainview
29 |
Mettler
Af |
Edison
33 |
Maricopa
29 |
Holland Creek
31 |
Tivy Valley
28 |
Kite Road South
31 |
Kite Road North
28 |
AF=Above Freezing
Air Quality Expectations: The San Joaquin Valley Air Pollution Control District has issued the following warning(s) for December 20, 2020:
The air quality for Madera, Fresno, and Kern Counties is unsafe for sensitive groups. The air quality for the remainder of the valley is moderate.
The District’s Real-time Air Advisory Network (RAAN) can be used to track air quality at any Valley location by visiting myRAAN.com. The option to use a specific address is available.
In addition, anyone can follow air quality conditions by downloading the free “Valley Air” app on their mobile device
Afternoon Dew Points Today: Low to mid 40s. Kern, upper 30s to the lower 40s.
Actual Humidity Range Yesterday: Delano, 95%/48% Porterville, NA
Percentage of Sunshine Today/Tomorrow: Visalia: Today: 40%, tomorrow 30%. Bakersfield: Today: 70% Tomorrow: 60%
ET Rates Over the Past Seven Days: Stratford .38, Parlier .27, Blackwell Corners .NA, Arvin .37, Orange Cove .26, Porterville .NA, Delano .32. Courtesy University of California *=estimate, NA=not available.
Seven Day Soil Temperatures: Stratford 54, Parlier 50, Blackwell 55, Arvin, 52, Orange Cove 54, Porterville 51, Delano 46
Record Temperatures: 70/24. Average Temperatures: 54/35
Heating Degree Days This Season: 709 -168 courtesy of the NWS
Average Temperature for this month So Far: 47.7 +2.7 courtesy of the NWS
Precipitation: Seasonal total for Fresno, 1.08, or -1.57, Month to Date: .80, or -.15
Precipitation for Bakersfield, Season, .40, +or- -1.11 Month to date .01, or -.56
Water year season is from October 1st through September 30.
Chilling Hours November 1st through February 28: Orange Cove, 384, Parlier, 465, Arvin, 383, Belridge, 466, Shafter, 433, Stratford, 442, Delano, 480, Porterville, 522
Hours at 45 or below 45. Courtesy UC Davis
Sunrise: 7:08 am Sunset: 4:47 pm Hours of Daylight: 9:38
Yesterday’s Weather
MCE : Merced 153 : DH1600 / 51 / 33 / 0.00 /
MAE : Madera 253 : DH1600 / 55 / 34 / 0.00 /
FAT : Fresno Airport 333 : DH1600 / 57 / 37 / 0.00 /
HJO : Hanford Airport 242 : DH1600 / 60 / 33 / 0.00 /
NLC : Lemoore Naval AS 234 : DH1600 / 59 / 26 / 0.00 /
BFL : Bakersfield Airport 496 : DH1600 / 61 / 35 / 0.00 /
VIS : Visalia Airport 292 : DH1600 / 58 / 32 / 0.00 /
ATEC1 : Avenal 787 : DH1537 / 60 / 58 / 0.00 /
PTV : Porterville Airport 442 : DH1600 / 61 / 31 / 0.00 /
Rainfall: 24hr W.Y. % Last Y. % Ave. Year ave.
STOCKTON 0.00 1.70 45 4.11 109 3.78 14.06
MODESTO 0.00 1.45 46 2.80 88 3.18 13.11
MERCED 0.00 2.10 77 0.00 0 2.74 12.50
MADERA 0.00 0.69 24 0.00 0 2.91 12.02
FRESNO 0.00 1.08 41 0.00 0 2.65 11.50
HANFORD 0.00 0.49 22 0.00 0 2.18 10.10
BAKERSFIELD 0.00 0.40 26 0.00 0 1.51 6.47
BISHOP 0.00 0.01 1 1.06 87 1.22 5.18
SALINAS 0.00 0.83 27 4.22 137 3.08 12.83
PASO ROBLES 0.00 0.30 11 4.73 173 2.73 12.78
SANTA MARIA 0.00 0.31 10 2.72 88 3.09 13.95
Next report: December 20/pm